Individual call-bell



3 Sheets--Sheet 1. F. B L A K B.

Individual Gall Bells. No. 232,442. Patented Sept. 21,1880.

. Fl -1- Inventor a, 9 7 2 I/WW P. BLAKE. 3 sheets sfiet 2.

Individual OaJllBells, No. 232,442. Patented Sept. 21, I880.

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PATENT FRANCIS BLAKE, OF WESTON, MASSACHUSETTS.

INDIVIDUAL CALL-BELL.

SPECIFICATION forming part of Letters Patent No. 232,442, datedSeptember 21, 1880.

' Application filed February 24,1ss0.

To all whom it may concern:

Be it known that I, FRANCIS BLAKE, of Weston, Massachusetts, haveinvented a new and useful Improvement in Individual 'Uall- Bells, ofwhich the following is a specification.

The invention consists in the employment of a number ofsynchronously-revolving dials under the control of a battery-currentupon a single circuit, but acting automatically, each at a separatetime, to ring a magneto-bell by diverting through or grounding throughthe magneto-bell a magneto-current generated at the central office, incombination with adevice, under the control of the operator at thecentral office, by which the automatic operation of the dial at thecentral office may be made to coincide with the automatic operation ofthe dial at either of the out stations.

It also consists in a deviceforshowing when the line is in use.

' It consists, further, in certain details of construction.

In the drawings, Figure 1 is a plan, and Fig. 2 a frontelevation, of aninstrument employed in carrying out my invention. Fig. 3 is a diagram,showing the circuit and branches when the invention is applied to agroup consisting of a central stationand two out stations, the magneto-bell to be run gbydiverting a magnetocurrent through it. Fig. 4is a diagram in further explanation of the working of the invention.Fig. 5 is a diagram in explanation of the working of the circuit whenthe magneto-bells of the out stations are to be rung by groundingthrough them the magneto-current gener ated at the central station. I

There is but a slight difference in the construction of the instrumentsbetween those adapted to circuits in which the magneto-bell is to berung by diverting a magneto-current and those belonging to circuits inwhich the magnetocurrent is to be grounded.

The instrument will first be described as be longing to a circuit of theformer kind.

A is a wooden table. B isa brass frame for a train of wheels or ordinaryclock-work, O, operated by a coiled spring, a. D is a dial up on ashaft, 0, revolving by the clock-work. F is a governing-fan. E is anelectro-magnet mounted upon a block, 6. H isits armature, rigidlysecured to a weighted bell-crank lever,

l, which, in turn, is rigidly secured to a post,

p, rocking on a pin, f, inserted in an arm, g,

projecting from the brass frame B. The bellcranklever carries a catch,m, which takes into a notch, n, in the periphery of the dial D,

and also a weight, 0, sufficiently heavy to lift the armature when notattracted by the electro-magnet. The dial D has a second notch,

n, for a purpose to be hereinafter mentioned. When the instruments areused in circuits in which the magneto-currentis to be diverted throughthe bell the dial is of metal and has a slot, which is filled with ahard-rubber plug,

1". When the instrument is to be used in circuits in which themagneto-current is to be grounded, the dial D is of hard rubber and theplugris of metal.

Pisa brass post in front of the dial, for

nishing a bearing for a metallic shaft, 13, carrying a hand or pointer,o. This hand is an electrode, and is furnished with a platinum point,which is at all times in contact with the dial, the plug 7 coming incontact with it at each revolution of the dial. The shaftt has a milledhead, by which it may be turned, and itis lockedin any required positionby a thumbscrew, it.

In the diagram, Fig. 3, B represents the brass frame with its train ofwheels; D, the brass dial; P, the post in front of the dial; t, itsshaft; o, the hand; and E the electro-magnet, all as in the instrumentabove described. B, D, P, t, o, and E represent like parts of a similarinstrument at station N o. l, and B D P t t and E like parts of asimilar instrument at station No. 2. The dials should be graduatedaccording to the number of stations, and each station have its ownnumber, its hand being turned to point to that number and there locked.That the hands may not get misplaced the milled heads may be removedfrom the shafts to which the hands are attached at the out stations.

Each station, including the central station, is provided with amagneto-bell, including a magneto-electric machine on the main line; andthe central station is furnished with a battery, as indicated, and akey, the spring-arm of which, in its normal condition, is in contactwith plate 13, but which, when depressed, is in contact with plate 14.

Each station is provided with four-screwcups, which, for convenience,are numbered in one series from 1 to 12. At the central station cups 1and 2 are connected with the battery by wires w and 10 and cups 3 and 4connect with a magneto-bell by wires 10 and w. Wires leading from cups 2and 3, from plate 13, and from onespool of the electro-magnet E, unite,as shown at x, and are marked 20 w, and w The other spool of theelectro-magnet E is connected by wire w with post P, while wire connectsthe brass frame, including its clock-Work O, with cup 4. A line-wire, w,connects cups at and 6, thus uniting the central station with stationNo. 1. At station No. 1 wires to and to connect cups 5 and 6 with abreak-circuit key, 3, belong ing to the station, to be used in giving areturn signal, as will be hereinafter described.

I Wires w and 10" connect cups 7 and S with a magneto-bell, and wire toconnects the two cups 6 and 7. Wire 20 connects cup 5 with a spool of anelectromagnet, E, the other spool being connected by wires 20 with postP, while wire to connects brass frame B with cup 8.

A line-wire, c0 connects stations No. 1 and No. 2 or cups 8 and 9. Atstation No. 2 wires @0 and it connect cups 9 and 10 with themagneto-bell. Wires w to connect cups 11 and 12 with the break-circuitkey 8 20 connects cup 12 with one spool of electromagnet E Wire wconnects the other spool with post P and wire to connects brass frame Bwith cup 9. Wire 10 conuectscups 10 and 11, the latter cup beinggrounded, as is likewise the spring-arm of the key at the centralstation.

In the diagram, 20 represents the ground part of the circuit, and wire@0 connects the key with cup 1.

It is evident from the above description that at each station, includingthe central station, the circuit is divided, one portion passing merelythrough the magneto-bell, while the other passes through theelectro-magnet and the dial-instrument.

It should be added that the battery-current is to be used simply foroperating the dial mechanism, the bells being rung by a magnetocurrent,and that the resistances of the different branches of the circuit ateach station are such that the bell will not ring while'the current isdivided at that station.

The battery-current is used as follows: In the normal condition of theline it is off, the arm of the key being in contact with the plate 13.at the central station the hand 4) is on the plug 4", for a reason to behereinafter stated; but when the operator at the central station isabout to put on the battery he turns his hand 1;, so that it is nolonger in contact with the plug 'r, but is in contact with the dial,at'the graduation thereof which corresponds with the position of thehand at the out station he wishes to call. Then depressing the key andWire 7 In the normal condition of the instrument bringing in thebattery, the circuit is from the ground-key through line @0 to cup 1,through the battery by wires to and 10 to cup 2, to junction 00, whereit divides, aportion passing by wire to through the electro-magnet, andby wire 10 post P, shaft t, hand 1), dial D, brass frameB, and wire 20to cup 4, whenceit passes through the other stations to ground, as willbe hereinafter shown. The other portion of the current passes fromjunction 00 by wire 20 to cup 3, and by wires 10 and to, through themagneto-bell, to cup 4, on to the other stations and ground. From cup 4the battery-current is by line-wire w to cup 6 in station No. 1, whereit again divides, a portion passing through wire 20 to cup 7, whence,passing through the magneto-bell by wires w and w, it passes to cup 8,on to the next station and ground, the other portion passing from cup 6by wires w to, through the break-circuit keys, to cup 5, and thenthrough the dial-instrument, by w" E 10 I t o D B @0 to cup 8, on to thenext station and to ground. .Entering the next station at cup 9 thecurrent divides, a portion passing through the magneto-bell and on togrounded cup 11 by 10 ,11), 10, and w, and a portion passing through thedial-instrument and break-circuit key to grounded cup 11 by w B D 712 tP 2.0 E @0 12 w s w.

When a single impulse of the batterycurrent is sent through the line theelectro-magnet at each station attracts its armature, and therebymomentarily lifts the stop from the notch 02 in the dial and allows thedial to be revolved by the clock-work, and the dial will 'j continue torevolve until the stop resting upon the periphery of the dial falls into the notch '11,.

The magneto'bells are of ordinary construction; but the invention may bemore easily unoperate the bell-striker at each station are stated. Theyare as follows:

At the central station wires 3 and 4 may be considered as a single-linewire, in which are located the coil of the electro-magnet of the strikerand a coil of the magneto-generator in such manner that these coils forma part of the line. In like manner wires 14 and 15 may be considered asa single-line wire at station 1, and wires 22 and 21 a sin gle-line wireat station 2, each having located in it, in like manner, correspondingcoils. The circuits for the magnetocurrents remain the same as thebattery-circuits, and itfollows'that a m agneto-current generated at thecentral station may be divided at cup 4, a portion being short-circuitedthrough the dial-instrument, or it may all pass over linewire 10 tostation 1. In like manner a magnetocurrent, of whatever strength,whichhas passed over wire 11 to station 1, may be divided at cup partlyshortcircuited or wholly passed through the magneto apparatus to ground;but, as before statedin substan ce,the resistances are such that thebell at no station can be rung unless the full magneto-current, wherevergenerated, passes through the magneto apparatus of that station. Itfollows that if the magneto-current generated at the central station bedivided at that station it will not ring its own bell, and it is obviousthat if a magneto-current generated at the central station cannot ringitsown bell it will not have suflicient strength to ring the bell ofanother station, whether the short circuit at that other station beestablished or broken. In other words, the short circuits, through thedial-instruments of both the'central station and of an out station mustboth be broken in order to ring the bell atthe out station by amagneto-current generated at the central station. Now, the dials are allgraduated, as before stated,and each station has its number. The normalposition of the hand at each.

station is upon the figure ot' the dial designating the number'of thestation,and at each revolution ot' the dialof any station, when the hand4) comes in contact with the plug r, the short circuit through the dialis broken. It

. follows that the operator at the central station,

knowing the position of the hands at the other stations, can set his ownhand to coincide with any one of the other bands, and that, genen atin ga magneto-current by his magneto-generator, he can send that currentthrough his own magneto-bell and through the magnetobell of that stationwhose hand so coincides with the hand at the central station. Those twobells will ring, and those only, for at all other stations themagneto-current will be short-circnited. Accordingly, to call an outstation, the operator at the central station will set the hand of hisdial to correspond with the hand of dial of the station he wishes tocall, send a single impulse of the battery-current through the line, andthen generate a magnetocurrent. The single impulse of the batterycurrentwill set all the dials in motion, and the bells of the central stationand the called station will ring at the same instant, which will be whenthe plugs of the dials of the two instruments come under theirrespective hands.

It is obvious that the operator at any out station may call the centralstation by generatin g a magneto-current with the generator of hismagneto-bell, provided he can break the short circuit through hisdial-instrument; but

since his dial is under the control of the bat-.

tery-current, which is operated from the central oftice, it becomesnecessary to furnish the short circuit at each out station withacircuitbreaker, as shown at 8, s and, Fig. 4, s.

A simple illustration of the invention as operated in atelephone-circuit consisting of a central and three out stations isshown at Fig. 4, in which the full line represents the main circuitpassing through the magneto-bells, as above described,'and also throughthe telecurrent with his magneto-generator. The nor- 7 5 mal position ofthe hand at central station is shown in dotted lines at Fig. 4--that is,it is upon the plug and the short circuit is broken. If the operator atstation 1 wishes to call the central station hehas merely to break hisown short circuit and operate his magneto-generator. The switch S at thecentral station is unnecessary, but is provided in order that thecentral station may be called, even if, through mistake or otherwise,the hand is not upon the 8 5 plug.

In Fig. 5, as before stated, the invention is illustrated'as used whenthe magnetocurrent is grounded through the magncto-bells. The dials arethen of hard rubber and the metal, and there can be no current of eitherdescription through the bell of any station unless the hand at thatstation is on the plug of the dial and as the hand at no station in itsnormal position is on the plug, the battery-current passes through theelectro-magnets E of the dial-instruments, and a single impulsewill setthe dials in motion, as heretofore described. When the circuits arearranged as shown in Fig. 5, there is no connection between plate 13 andthe line, and in the normal condition of the line the current is brokenat the key. The devices shown at 8, s and 8 instead of beingcircuit-breakers, are circuit-maker.s.

In'this system as worked with grounded bells a resistancecoil is placedin the main line beyond the farther station, of such power that amagneto-current generated upon the line will pass through an interveningmagneto-bell to ground whenever an opportunity ofiers, and this happenswhenever the hand at a station is on the plug.

The operation is as follows: The operator at the central station,wishing to call another station, sets the hand at his station so that itpoints in the same direction as the hand at the station he wishes tocall. Touching the key, he then sends a single impulse through the line,setting all the dials in motion, when he generates amagncto-current inhis magnetomachine;

It is obvious that this magneto-current can be established on the mainline only when the plug comes under the hand at the central station, andit is also obvious that it will ground through the bell at that stationthe plug of whose dial comes under the hand at the same time. Whengrounded bells are used the hand is upon the plug at the centralstation, or the switch S is closed, so that the bell may be rung by anyperson generating a magneto-current at any out station.

plug of 4 v :eeama The notch it prevents the dial from making a fullrevolution, and when the catch on is in the notch n it is evident thatthe plug 4" will be in a different position from that which it occupieswhen the catch is in the notch 42. Use is therefore made of this deviceas a line-inuse signal. The operator at the central station allowing allthe catches to remain in the notches a while the line is in use, theperson at the out station seeing that his own plug is out of its normalplace, will know that the line is in use.

It is obvious that in this system either station may be used as acentral station, provided it has a suitable battery and key-that is, thebell of any single station may be rung from any other station.

I claim- 1. A number of synchronously revolving dials controlled by abattery-current but acting automatically, each at its own time, to ringa m agneto-bell by diverting through or grounding through themagneto-bell a magneto-current generated at a distant office, incombination with an automatic device under control of 25 the operator atthe distant office, by which the automatic operation of the dial at thedistant oftiee may be made to coincide with the automatic operation ofeither of the other dials.

2. In combination with a battery, suitable wires, and a magneto-bell,the hand 4), electro magnet E, armature H, provided with a catch, m, anddial D, provided with notch n and plug r, the dial or plug forming oneelectrode and the hand a second electrode, substantially as described,for the purpose specified.

3. At each of a number of stations on a telephone or telegraph line, adial revolved by its own clock-work and provided with two notches orstopslocated relatively to each other and working in combination withthe weighted armature of an electro-magnet, substantially as described,to show at any and all the stations whether or not the line is in use.

FRANCIS BLAKE.

Witnesses SAM. W. Barns, H. G. OLMSTED.

